Power driven, manually guided lawn mower



.April 18, 1939. F. EISENLOHR POWER DRIVEN, MANUALLY GUIDED LAWN MOWER 5Sheets-Shee t 1 Filed July 26, 1937 'I'Illll'lL April 18, 1939. FEISENLOHR I POWER DRIVEN, MANUALLY GUIDED LAWN MOWER- Filed July 26,1957 3 Sheets-Shet 2 H L l Jm en/ar: Z7 ZZren/II April 18, 1939. F.EiSENLOHR 2,154,564

POWER DRIVEN, MANUALLY GUIDED LAWN MOWER I Fild July 26, 1937 3Sheets-Sheet 3 Patented Apr. 18, 1939 UNITED STATES rowan DRIVEN, mumsormmn LAWN mowsn- Friedrich 'Eisenlohr, swarm-sac cmma,

Germany, assignor to G. Staehle Kommandltgesellschaft. ml!!! ApplicationClaims This invention relates to a power-driven, manually guided lawnmower with not less than one blade rotating in a horizontal plane, atruck motor having a vertical shaft whose lower end' projects from themotor casing. A pulley may be mounted on this end and suitable means,for instance, a belt of triangular cross-section, may be connected tothe pulley for driving the blade, or blades. If several blades areprovided their axes of rotation may be arranged in the elongation of themotor-shaft axis, or symmetrically to the axis.\ Instead, a single blademay be mounted directly on the lower end of the motor shaft.

A particular feature of the invention resides in that the truck, theblade, or blades, and the blade rotating means together make up aselfcontained unit which is used as an accessory to the well-knownhousehold floor cleaner in which 25 not less than one rotatory brush isdriven from the vertical shaft .of an electric motor.

Floor cleaners of the kind described have already been subdivided intotwo self-contained units with a detachable connection between them. soThe upper unit includes the motor and its casing, a suitable cowl inwhich themotor casing. is housed, and a rod for guiding'the floorcleaner. The lower unit includes the brush, or brushes. It has alreadybeen proposed to replace the lower 35 unit, with its brush, or brushes,by a suction nozzle detachably connected to the upper, or motor, unit.It is a very important improvement of the fl cleaner that its upper unitby connecting thereto 40 a lower unit designed in accordance, with theinvention can be used for lawn mowing. In the drawings two embodimentsof the inventlon are illustrated by way of example.

Fig.1 is aperspective, and partly sectional, 4g illustration of a floorcleaner whose lower unit is detachable and can be replaced by a mowerunit according to the invention. k

Fig. 2 is a vertical longitudinal section and 3 is a plan view, of thefirst embodiment. m Fig. 5 is a partial section in the planeof the motoraxis, showing the second embodiment.

The floor cleaner, Fig. 1. comprises an upper unit A and a lower unit Bwhich are detachably 5 connected.

4 is a partly sectional end elevation, and- Stuttgart-Bad, Cannstatt,Ger- July 26; 1937, Serial No. 155,768 Germany August 8, 1986 l Theupper unit A supports the casing I of a vertical electric motor. .Thelower end 2 of the motor shaft projects from the lower end of the casingi. Just below the casing,'a fan impeller 3 is keyed on the shaft end. Acowl l surrounds 5 the motor casing i and the impeller 3 in spacedrelation and is equipped with a pipe i for con: nection to a filter bag6.. The forked lower end of a tubular guide rod. I is connected to thecowl 4 by suitable trunnions and a cable 8 for supply- 10 ing current tothe motor is concealed in the tubular rod.

In the lower unit B two circular brushes 5 are mounted to rotate aboutvertical shafts for cleaning, or waxing, a floor. The lower end 2 of the16 motor shaft projects into the lower unit B and is connected to thebrush shafts by friction pulleys.

A readily detachable connection between the two units is preferablydesigned as shown for 20 the second embodiment in Fig. 4. Two studs illwith helical grooves project upwardly from opposite sides of the truckand sleeves l0 each with a handle at its upper end and a pair ofinwardly projecting lugs it near its lower end, are mounted to turn andto be shifted axially on the upper unit A. When the upper unit is placed'on the lower unit from above, the lugs ll of each sleeve engage inthehelical grooves of the corresponding stud and the two units are finallyconnected by turning the handles of the sleeves.

The first embodiment of a lower unit B for converting a floor cleaner,or waxer, into a lawn mower will now be described with reference toFigs. 2 and 3.

' A hollow cylinder projects downwardly from the lower end of a cup IIin which the bottom plate of the cowl l is seated at its upper end whenthe two units A and B are assembled, as best seen in Fig. 5. Ballbearings for a hollow driving 40 shaft 12 are inserted in the cylinder.Power is transmitted to the hollow driving shaft I! from the lower end 2of the motor shaft through the medium of a square member 21 which issecured on, or made integral with, the shaft. A flange 2Ov is secured tothe upper end' of the hollow driving shaft l2 and a clutch member 29, ofresilient material such as rubber with insertion of canvas, is rivetedor otherwise secured to the upper annular face of the flange 2!. A powertransmitting member Ill is connected to the central portion of theclutch member 29 by screws or rivets, and the square member 21 on themotor shaft engages in a corresponding hole of the ring ll. When themotor rotates, the rotation ception of a belt ll having triangularcross-- section, is secured to the lower end of hollow driving shaft I!by a tap bolt 3|. The belt II connects the driving pulley II to a drivenpulley 62 .whose hollow and elongated boss has ball bearings forrotation about a stationary shaft II at the lower end of a stay It. Thestay I.

engages in an elongated hole of a plate It whose front end is formedwith a semi-cylindrical flange to engage one side of the cylinder at thelower end of cup ll while a bracket Ila, Fig. 3, engages the other sideof,the cylinder and is connected to the flange on the plate I! by bolts54.

A flange II whose front portion is cut away as shown in Fig. 3 is formedat the upper end ofthe cup H asbestseenin Fig.5. Astayil is inserted ina hole at the rear end of the flange to brace the plate It against theflange and the studs II are secured to the flange. Y I! is the top plateof the frame ll of the truck which has the shape of an inverted U, withtwo side plates depending from the top plate II. This plate is cut awayat its front end to clear the cowl 4 and the studs II andissecuredtotheflange ll" by four screws. The hole for the stay It in the make theother pair of edges lead, and regrinding is only required when all fouredges have become blunt.

The truck is supported by a pair of leading wheels SI and a pair oftrailing wheels 8!. The leading wheels are mounted together in a bracket'0.

The journals 02 of the trailing wheels II are held in the side plates5'" and a plurality of superimposed holes 03, Fig. 2, are made in eachside plate so that the level of the trailing wheels with respect to thetruck can be varied by placing their journals '2 in other holes I.

The leading-wheel bracket II is mounted to swivel about a pivot N in anextension Ii" of the flange il'. between the extension II" and thebracket I,

spacingrlnssliareinserted 2,154,504 of its shaft is transmitted to theshaft l2 and between the extension and a nut at the upper end of thepivot I so that, by removing and insetting certain spacing rings I. thelevel of the leadingwheelsisadaptedtothatofthetrailing wheels, and theblade I! is supported at the desired distance from the grolmd It. If allspacing rings 05 are placedbetween the extension II" and the nut at theupper end of the pivot, and the trailing wheels 60 are arranged inconformity, the blade '8 will be at the shortest distance from theground it. If one, or more, spacing rings 15' are inserted between theframe I. and the extenarrangedin conformity, the blade is placed at acorrespondingly greater distance above the ground It.

A check II is riveted to the lower side of the extension I I" to limitthe movement of frame ll about its pivot 84.

Referring now to Figs. 4 and 5, this embodiment of the invention issubstantially similar to the first one but here the pulleys II and I!are dispensed with and the blade II is secured directly to the hollowshaft I! by the tap bolt ll instead of pulley ll, Fig. 2.

I claim: r

I. A convertible device comprising the combination of a householdcleaning and waxing appliance including a. casing, a motor in saidcasing and a motor shaft for driving tools supported for rotation bysaid casing, with at least one horizontally revolving lawn cuttingblade, a portable truck surrounding and supporting said blade.

' means for regulating the height of cutting of said blade, a hollowshaft iournaled in said truck and detachably fltted over and driven bysaid motor shaft. a driving connection between said hollow shaft andsaid blade, said blade, regulating means, truck, hollow shaft anddriving connection constituting an implement attachable to anddetachable from the casing of said appliance.

2. A device as claimed in claim 1 characterized by the provision of aflexible coupling forming a driving connection between said shafts.

3. A device as claimed in claim 1 characterized in that said drivingconnection includes pulleys connected respectively with the hollow shaftand the revolving blade, a belt drive connecting said pulleys, and meansfor adjusting the pulley of the revolving blade for adjusting thetension of the belt; drive. i

' 4. A device as claimed in claim 1 characterized in that said truckincludes supporting wheels and a frame, and means for adjusting saidwheels with respect to said frame. 7

5. A device as claimed in claim 1 characterized in that said blade isprovided with straight side edges and curved end edges, both edges beingformed to produce cutting edges.

FRIEDRICH EISENLQHR.

